Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that results in death, usually from respiratory insufficiency or aspiration, within 3 to 5 years of diagnosis. The disease affects all voluntary motor function except eye movement and sphincter control. In the final 6-9 months of life, patients must choose (either explicitly or by default) palliation or tracheostomy and long-term mechanical ventilation (LTMV). In this 4 year project, we will follow 140 patients diagnosed with definite or probable ALS who face a high likelihood of death within 6-9 months, as defined by poor pulmonary function, dysphagia and weight loss, or hospice certification or eligibility. These patients will be followed with bimonthly in-home assessments, and with an additional assessment in the last weeks of life. We will also interview the primary family caregiver on the same schedule and once after the patient's death, as well as conduct a survey of medical providers' influence on end-of-life decisions. In this observational cohort study, we propose (1) to assess the prevalence and course of depressive disorders and symptoms in ALS patients in the final months of life and its relevance for decision-making at the end of life; (2) to identify predictors of tracheostomy/LTMV use; (3) to examine the degree to which patients and families take steps to control the timing of death by adopting a strict palliative care regime; and (4) to examine associations between patient and caregiver distress in the final months of life. Key questions include the following: Do levels of distress and depressive symptoms increase as patients approach death, and does this relationship differ according to choice of palliative care or LTMV? What maintains hope in these patients, who are, in a medical sense, hopelessly ill? Of patients who receive LTMV, in what proportion is LTMV consciously planning for, as opposed to an unplanned emergency procedure? Is patient mental health or caregiver burden associated with decisions to forego or undergo LTMV? To what degree does use of non-invasive, temporary nasal ventilation (Bi-Pap) prevent use of LTMV? These questions have not been investigated in a prospective study. We will be able to address them through repeated, detailed assessments of patients and caregivers. This information will be critical for understanding the experience of patients with terminal disease as they and their families face end-of-life care decisions.